For the first time, Swedish scientists from the Linköping University combined one of Mother Nature's vascular systems with modern electronic circuit.
Professor Magnus Berggren, Linköping University's Strategic Research Centre for Organic Bioelectronics director and Organic Electronics professor, led the groundbreaking research where a living plant's vascular system was used to create an electronic circuit's key mechanisms. The team at Laboratory of Organic Electronics (LOE) is hopeful that the cutting-edge research would give birth to organic electronics and new tools.
To perform certain internal functions, plants depend on hormone and ionic signals movement. However, the plant's slow operational timeline made intervention difficult, becoming a challenge to many scientists. The Swedish researchers used electronic signals to tap into the plant's chemical processes, making way for a merger that allowed the team to interact with the plant's chemical pathways and enable them to control the growth regulators, photosynthesis-based fuel cells and other devices that play roles in the plant's internal functions.
"Previously, we had no good tools for measuring the concentration of various molecules in living plants. Now we'll be able to influence the concentration of the various substances in the plant that regulate growth and development," said study co-author Ove Nilsson, plant reproduction biology professor and Umeå Plant Science Center director.
The idea of embedding electronics into trees began in the 1990s when the LOE team were studying the potential of printed electronics for the paper industry. Professor Xavier Crispin, leader of the LOE's solid-state device team and assistant professor Daniel Simon, LOE's bioelectronics team leader work on the project's first few attempts. Due to lack of funding, the projects were put on hold.
In 2012, Knut and Alice Wallenberg Foundation granted new research money to revive the halted project. Now led by Professor Berggren, the new research team tried embedding various conductive polymers via a rose's stem. A polymer called PEDOT-S emerged as the only successful polymer and rooted itself as conducting wires inside the plant's xylem channels. The merger was able to retain water and nutrients transports.
The combination led to the creation of an electrochemical transistor that converts ionic signals into electronic output. The research team then sucked out the air from the rose's leaf and filled it with the same polymer using the vacuum infiltration process. This lead to the creation electrochemical cells pixels segregated by the veins. When voltage was applied, the polymers interacted with the leaf's ions causing it to change color.
"As far as we know, there are no previously published research results regarding electronics produced in plants. No one's done this before," said Berggren.
The early findings could eventually lead to the development of sustainable and environmental energy applications using organic electronics. The research was published in the journal Science Advances.